Error LNK2019

This is a code I've written for Random Directed Acyclic Graph Generation:

Code:

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#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <time.h>


using namespace std;


int random_or_user_defined( void );
int random_weight_generation( int, int );
int randvert ( void );
int fixedvert ( void );
int random_edge_generation( int );
int connflagcheck( int, int, int );
int vnum, **edge, *connflag, **weight;


int main( void )
{
    random_or_user_defined();
   
    srand (time(NULL));


    random_edge_generation( vnum );


    random_weight_generation( vnum, **edge );


    return 0;


}


int random_or_user_defined( void )
{
    char opt;
   
    cout<<"Do you want to manually enter the number of vertices?";
    cout<<endl<<"Press Y for yes, N for no."<<endl;
    cin>>opt;


    while (( opt != 'Y' ) && ( opt != 'y' ) && ( opt != 'N' ) && ( opt != 'n' ))
    {
        cout<<"Wrong input! Try again: ";
        cin>>opt;
    }


    if (( opt == 'Y' ) || ( opt == 'y'))
    {
        randvert( );
    }
    else if (( opt == 'N' ) || ( opt == 'n' ))
    {
        fixedvert( );
    }   
   
    return vnum;


}




int randvert ( void )
{
    int vnum_max;


    cout<<"Enter the number of maximum vertices: ";
    cin>>vnum_max;
   
    while (vnum_max < 2)
    {   
        cout<<"A graph with one vertex is inadmissible."<<endl<<"Enter a number greater than 1. ";
        cin>>vnum_max;
    }


    srand (time(NULL));
    vnum = (rand()%vnum_max) + 1;
   
    cout<<"Number of vertices chosen: "<<vnum;
   
    return vnum;
}


int fixedvert ( void )
{
    cout<<"Enter the number of vertices: ";
    cin>>vnum;
   
    return vnum;
}


int random_edge_generation( int vnum )
{
    int i, j, k, **edge;


    edge = (int **) malloc ( vnum * sizeof (int* ) );
       
    for(i = 0; i < vnum; i++)
    {
        edge[i] = (int *) malloc ( vnum * sizeof (int) );       
    }


    connflag = (int *) malloc ( vnum * sizeof (int) );
   
    for ( i = 0; i < vnum; i++ )
    {
        connflag[i] = 0;
       
        for ( j = 0; j < vnum; j++ )


            edge[i][j] = 0;
    }


   
    for ( i = 0; i < vnum; i++ )
    {
        for ( j = vnum - 1; j > i; j-- )
        {
            if (rand()%2 == 1)
            {
                edge[i][j] = 1;
                connflag[j] = 1;
            }


        }
    }


    connflagcheck( *connflag, **edge, vnum );


    return 0;
}


int connflagcheck( int *connflag, int **edge, int vnum )
{
    int i;
    char opt;


    cout<<"Will you allow disconnected graph? Press Y or N: ";
    cin>>opt;
   
    while (( opt != 'Y')&&( opt != 'y' )&&( opt != 'N' )&&( opt != 'n' ))
    {
        cout<<"Wrong input! Try again: ";
        cin>>opt;
    }
    if (( opt == 'N' ) || ( opt == 'n' ))
    {
   
        for ( i = 1; i < vnum; i++ )
        {
            if ( connflag[i] == 0 )
            {
                edge[rand()%i][i] = 1;
            }
        }
    }


    return **edge;
}


int random_weight_generation( int vnum, int **edge )
{
    int i, j, wmax;


    cout<<"Enter the maximum weight: ";
    cin>>wmax;


    weight = (int **) malloc ( vnum * sizeof (int *) );
       
    for(i = 0; i < vnum; i++)
    {
        weight[i] = (int *) malloc ( vnum * sizeof (int) );       
    }


    for ( i = 0; i < vnum; i++ )
    {
        for ( j = vnum - 1; j > i; j-- )
        {
            if ( edge[i][j] == 1 )
            {
                weight[i][j] = (rand() % wmax) + 1;
            }


        }
    }


    return **weight;
}

---

However this gives two LNK2019 error codes. I'm new to coding, so can anyone help me out? I'd like to learn what I'm doing wrong.

Please post the complete error messages, exactly as they appear in your development environment.

Jim

Thank you for your swift reply. The errors I'm seeing are as follows:

source1.obj : error LNK2019: unresolved external symbol "int __cdecl random_weight_generation(int,int)" (?random_weight_generation@@YAHHH@Z) referenced in function _main
source1.obj : error LNK2019: unresolved external symbol "int __cdecl connflagcheck(int,int,int)" (?connflagcheck@@YAHHHH@Z) referenced in function "int __cdecl random_edge_generation(int)" (?random_edge_generation@@YAHH@Z)
source1.exe : fatal error LNK1120: 2 unresolved externals

You declared a function called random_weight_generation() with two int parameters. Where did you implement this function?

Note you implemented a function with that name but with one int parameter and one int** parameter, this will be treated as a different function by the compiler.

Your function declaration (prototype), function call, and your function implementation must all agree as to the number and type of parameters.

Jim

I find it disturbing that you are using malloc in C++, and that you are allocating 2d arrays manually.
I urge you to google 2d vector c++. Also, switch your C headers to C++ headers: Add c and remove .h, eg time.h --> ctime.

Quote:

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Mycroft Holmes

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O_o

Wow. He would be the very best programmer ever.

Soma

Thank you for all your replies. I'll try to rectify my code and run it again. And Elysia, thanks for telling me about two-dimensional vectors. However, I could find a thorough guide for multidimensional vectors, and so I'm in the dark about its implementation. Perhaps, you might share a few link or two about it. That'd really help.

Quote:

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Originally Posted by phantomotap

Wow. He would be the very best programmer ever.

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Elementary, my dear Thompson.

Quote:

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Originally Posted by Mycroft Holmes

Thank you for all your replies. I'll try to rectify my code and run it again. And Elysia, thanks for telling me about two-dimensional vectors. However, I could find a thorough guide for multidimensional vectors, and so I'm in the dark about its implementation. Perhaps, you might share a few link or two about it. That'd really help.

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What is wrong with Initialising 2D vectors - C++ Forum?

Thank you, Elysia.